Implementation of a TSMCSPO Controller on a 3-DOF Hydraulic Manipulator for Position Tracking and Sensor-Less Force Estimation

Abstract

In this study, a three-degree-of-freedom hydraulic system device configured as a masterand-slave manipulator system is considered. A methodology to estimate reaction force in aforementioned system is proposed without utilizing any force sensor/signal. A terminal sliding control with a sliding perturbation observer (TSMCSPO) is designed for coupled master-slave system. The fundamental benefit of the proposed scheme is that the sliding perturbation observer estimates the reaction force related to the end effector and second link without utilizing a force sensor. Robust and accurate position tracking is achieved with terminal sliding-mode control in addition to control of the slave manipulator. The position and force tracking for master-slave is estimated based upon bilateral control strategy. The difference in the reaction and operating force is included in the impedance model. The impedance model is implemented in the master device to provide the operator with a sense of the reaction force when it connects with the environment. The experimental results confirm the robust position and force tracking of the slave manipulator.

Force-Free Control for Direct Teaching of a Surgical Assistant Robot End Effector with Wire-Driven Bidirectional Telescopic Mechanism

“…The Lu-Gre model applied in this study has the advantage of not having a large computational load, while describing the friction characteristics well; thus, it is used for modeling various motor drive systems [15,16]. The LuGre model is expressed as Equation (8). z is an internal variable of the friction model, which represents the average deflection of the bristle.…”

“…There are two dynamic parameters: Bristle stiffness and bristle damping coefficient. The dynamic parameters can be obtained by comparing the results of Equation (8), in which the static parameter values are substituted, with the experimental results. The velocity control input frequency of the motor is given in sine waves of 0.1 Hz, 0.2 Hz, 0.5 Hz, and 1.0 Hz, while the torque is estimated from the obtained current value.…”

“…The external force is estimated from the current value of the motor, and torque control is performed accordingly [ 3 , 4 ], while Zeor Moment Point is also performed at each joint position of the robot [ 5 ]. Torque control and impedance control are widely applied in direct teaching [ 6 , 7 ], and observers are also designed to estimate accurate friction models [ 8 , 9 ]. In this study, force-free control based on position control is applied.…”

Empirical Modeling of 2-Degree-of-Freedom Azimuth Underwater Thruster Using a Signal Compression Method

“…Signal compression methods are often used for the empirical modeling of mechanical systems and can extract the frequency response of a system in the whole range of mechanically constrained frequencies using a pseudo-impulse signal [22]. Signal compression methods have been used for the cylinder modeling of an automatic excavator [23] and friction modeling of a robot manipulator [24]. In repeated experiments, the velocity profile of the pseudo-impulse input was applied to the two rotational axes, and the frequency response of the longitudinal thrust force, lateral thrust force, and reaction moment were analyzed with a Bode plot.…”

DPSO and Inverse Jacobian-Based Real-Time Inverse Kinematics With Trajectory Tracking Using Integral SMC for Teleoperation

“…To remove the chatter, a non-linear compensator, known as sliding perturbation observer (SPO) [39,40], is introduced. The SPO uses the partial feedback (position only) of the system to eliminate the effect on nonlinearities from the system response by estimating the system state and perturbation (non-linearities, uncertainties, and disturbances); this estimated perturbation is useful in removing the chatter [41]. The integration of the SMC with the SPO (SMCSPO) produces a robust non-linear controller even in the presence of non-linearities [42].…”