Position-Mode Haptic-Based Control of Teleoperated Hydraulic Actuators

2011 ◽  
Author(s):  
Kurosh Zarei-nia ◽  
Nariman Sepehri
Keyword(s):  
Invariant Set ◽  
Haptic Device ◽  
Position Tracking ◽  
Good Position ◽  
View Point ◽  
Hydraulic Actuator ◽  
Control Laws ◽  
Hydraulic Actuators ◽  
Control Scheme ◽  
On Line

A control scheme for teleoperation of hydraulic actuators, using a haptic device, is developed and experimentally evaluated in this paper. In the control laws, the position error between the displacement of the haptic device and the hydraulic actuator movement is used at both master and slave sides to maintain good position tracking at the actuator side while providing a haptic force to the operator. Lyapunov’s stability theory and LaSalle’s invariant set theorems are employed to prove the asymptotic stability of the system. It is shown that beside stability, the system performs well in terms of position tracking of the hydraulic actuator and providing a feel of telepresence to the operator. Proposed controller only needs system’s pressures and displacements that are easy to obtain via on-line measurements. Additionally, the controller does not need any information about the parameters of the system. These characteristics make the controller very attractive from the implementation view point.

Asymptotic Impact Control of Hydraulic Actuators With Friction

2004 ◽  
Author(s):  
P. Sekhavat ◽  
N. Sepehri ◽  
Q. Wu
Keyword(s):  
Steady State ◽  
Nonlinear Control ◽  
Dry Friction ◽  
Position Control ◽  
Past Research ◽  
Hydraulic Actuator ◽  
Stick Slip ◽  
Hydraulic Actuators ◽  
Control Scheme ◽  
Control Schemes

The focus of this work is stabilization of hydraulic actuators during the transition from free motion to constraint motion and regulating the intermediate impacts that could drive the system unstable. In our past research, we introduced Lyapunov-based nonlinear control schemes capable of fulfilling the above goal by resting the implement on the surface of the environment before starting the sustained-contact motion. The hydraulic actuator’s stick-slip friction effect was, however, either not included in the analysis or not compensated by the control action. In this paper, the application of our previously introduced friction compensating position control scheme is extended to impact regulation of a hydraulic actuator. Theoretical solution and stability analyses as well as actual experiments prove that such control scheme is also effective for asymptotic impact control (with no position steady-state error) of hydraulic actuators in the presence of actuator’s dry friction.

The modeling and controlling of electrohydraulic actuator for quadruped robot based on fuzzy Proportion Integration Differentiation controller

2014 ◽  
Vol 228 (14) ◽  
pp. 2557-2568 ◽  
Author(s):  
Xu Zhe ◽  
Gao Junyao ◽  
Li Hui ◽  
Liu Huaxin ◽  
Li Xin ◽  
...  
Keyword(s):  
Fuzzy Logic ◽  
Control Strategy ◽  
Fuzzy Logic Controller ◽  
Fuzzy Controller ◽  
Quadruped Robot ◽  
Outdoor Environment ◽  
Position Tracking ◽  
Hydraulic Actuator ◽  
Hydraulic Actuators ◽  
Flexible Loads

Hydraulic actuators are widely used in various kinds of industrial applications. High-power density is key parameters for engineering applications especially for quadruped robots applied in the outdoor environment. Therefore, an increasing number of advanced robots are equipped with hydraulic actuators. In this paper, to compensate the inherent nonlinearities and enhance the performance of the quadruped robot, a hybrid fuzzy controller composed of fuzzy logic controller and Proportion Integration Differentiation controller is evaluated both in simulations and experiments. The control strategy is developed based on the accurate mathematical model. The Matlab Simulink and Fuzzy Logic Toolbox are implemented to accomplish the simulations under flexible loads. Single hydraulic actuator and single leg experiments are accomplished on the specific platforms. Both the simulations and the experimental results indicate that the fuzzy Proportion Integration Differentiation control strategy is capable of fulfilling the specific position tracking under diverse loads. Compared with the conventional Proportion Integration Differentiation controller, the fuzzy Proportion Integration Differentiation controller provided a desirable performance under heavy load with comparatively little response and settling time. Results show that the fuzzy Proportion Integration Differentiation control strategy can effectively achieve the objective of enhancing position tracking robustness under flexible loads and improve the performance of quadruped robot.

A Hybrid Haptic Sensation for Teleoperation of Hydraulic Manipulators

2015 ◽  
Vol 137 (9) ◽  
Author(s):  
Kourosh Zareinia ◽  
Nariman Sepehri
Keyword(s):  
Force Feedback ◽  
Experimental Studies ◽  
Interaction Force ◽  
Position Tracking ◽  
Hydraulic Actuator ◽  
Hydraulic Manipulators ◽  
Nonsmooth Systems ◽  
Control Scheme ◽  
The Stability ◽  
Haptic Sensation

In this paper, a control scheme is designed for stable haptic teleoperation of hydraulic manipulators. The controller results in a stable position tracking for the hydraulic actuator (slave) in both unconstrained and constrained motions. The force feedback at the haptic (master) side is a combination of two different sensations. For free motion, the haptic device provides a haptic force based on the position error between the displacements of the master and the slave. The force also serves to alert the operator when the slave is ahead or behind in position tracking of the master. Once the slave comes in contact with the environment, the haptic force is augmented by the interaction force. The uniqueness, continuation, and existence of the Filippov solution to this system with the discontinuity surfaces are proven first. The extension of Lyapunov's stability theory to nonsmooth systems is then employed to prove the stability by constructing a Lyapunov function. The effectiveness of the controller is validated via experimental studies. It is shown that while stable, the system performs well in terms of position tracking of the hydraulic actuator and providing a haptic feel to the operator. The measurements required by the controller are supply pressure, actuator's line pressures, interaction force, and displacements of the master and slave.

scholarly journals Formation Tracking Control and Obstacle Avoidance of Unicycle-Type Robots Guaranteeing Continuous Velocities

Sensors ◽  
2021 ◽  
Vol 21 (13) ◽  
pp. 4374
Author(s):  
Jose Bernardo Martinez ◽  
Hector M. Becerra ◽  
David Gomez-Gutierrez
Keyword(s):  
Obstacle Avoidance ◽  
Tracking Control ◽  
Global Coordinate System ◽  
Avoidance Task ◽  
Time Varying ◽  
Control Laws ◽  
Formation Tracking ◽  
Control Scheme ◽  
First Time ◽  
Hierarchical Scheme

In this paper, we addressed the problem of controlling the position of a group of unicycle-type robots to follow in formation a time-varying reference avoiding obstacles when needed. We propose a kinematic control scheme that, unlike existing methods, is able to simultaneously solve the both tasks involved in the problem, effectively combining control laws devoted to achieve formation tracking and obstacle avoidance. The main contributions of the paper are twofold: first, the advantages of the proposed approach are not all integrated in existing schemes, ours is fully distributed since the formulation is based on consensus including the leader as part of the formation, scalable for a large number of robots, generic to define a desired formation, and it does not require a global coordinate system or a map of the environment. Second, to the authors’ knowledge, it is the first time that a distributed formation tracking control is combined with obstacle avoidance to solve both tasks simultaneously using a hierarchical scheme, thus guaranteeing continuous robots velocities in spite of activation/deactivation of the obstacle avoidance task, and stability is proven even in the transition of tasks. The effectiveness of the approach is shown through simulations and experiments with real robots.

A Hierarchical Access Control Scheme Based on Lagrange Interpolation and ELGamal Algorithm with Numerical Experiments

2013 ◽  
Vol 385-386 ◽  
pp. 1705-1707
Author(s):  
Tzer Long Chen ◽  
Yu Fang Chung ◽  
Jian Mao Hong ◽  
Jeng Hong Jhong ◽  
Chin Sheng Chen ◽  
...  
Keyword(s):  
Access Control ◽  
Lagrange Interpolation ◽  
Control Mechanism ◽  
Key Generation ◽  
Electronic Documents ◽  
Control Scheme ◽  
Video Systems ◽  
Efficient Scheme ◽  
On Line ◽  
Access Control Mechanism

It is important to notice that the access control mechanism has been widely applied in various areas, such as on-line video systems, wireless network, and electronic documents. We propose an access control mechanism which is constructed based on two mathematical fundamentals: Lagrange interpolation and ElGamal algorithm. We conduct performance analysis to compare the efficiency of our proposed scheme with that of several related published schemes in both key generation phase and key derivation phase. Our new scheme is proven to be more efficient. It is shown, as expected, a more efficient scheme provides relatively less security and a more secure scheme is relatively less efficient for private keys of the same size.

The Optimization of Time-Frequency Control: Using Non-Autonomous Time-Delay Feedback Systems as Example

2016 ◽  
Author(s):  
Chi-Wei Kuo ◽  
C. Steve Suh
Keyword(s):  
Time Delay ◽  
Dynamic Instability ◽  
Frequency Control ◽  
Frequency Resolution ◽  
Control Technique ◽  
Time Step ◽  
Time Frequency ◽  
Control Scheme ◽  
Fxlms Algorithm ◽  
On Line

A novel time-frequency nonlinear scheme demonstrated to be feasible for the control of dynamic instability including bifurcation, non-autonomous time-delay feedback oscillators, and route-to-chaos in many nonlinear systems is applied to the control of a time-delayed system. The control scheme features wavelet adaptive filters for simultaneous time-frequency resolution. Specifically Discrete Wavelet transform (DWT) is used to address the nonstationary nature of a chaotic system. The concept of active noise control is also adopted. The scheme applied the filter-x least mean square (FXLMS) algorithm which promotes convergence speed and increases performance. In the time-frequency control scheme, the FXLMS algorithm is modified by adding an adaptive filter to identify the system in real-time in order to construct a wavelet-based time-frequency controller capable of parallel on-line modeling. The scheme of such a construct, which possesses joint time-frequency resolution and embodies on-line FXLMS, is able to control non-autonomous, nonstationary system responses. Although the controller design is shown to successfully moderate the dynamic instability of the time-delay feedback oscillator and unconditionally warrant a limit cycle, parameters are required to be optimized. In this paper, the setting of the control parameters such as control time step, sampling rate, wavelet filter vector, and step size are studied and optimized to control a time-delay feedback oscillators of a nonautonomous type. The time-delayed oscillators have been applied in a broad set of fields including sensor design, manufacturing, and machine dynamics, but they can be easily perturbed to exhibit complex dynamical responses even with a small perturbation from the time-delay feedback. These responses for the system have a very negative impact on the stability, and thus output quality. Through employingfrequency-time control technique, the time responses of the time-delay feedback system to external disturbances are properly mitigated and the frequency responses are also suppressed, thus rendering the controlled responses quasi-periodic.

scholarly journals Position Tracking Performance with Fine Tune Ziegler-Nichols PID Controller for Electro-Hydraulic Actuator in Aerospace Vehicle Model

2021 ◽  
Vol 2107 (1) ◽  
pp. 012064
Author(s):  
S.M. Othman ◽  
Noorhazirah Sunar ◽  
Hassrizal H.B ◽  
A.H. Ismail ◽  
M.N. Ayob ◽  
...  
Keyword(s):  
Pid Controller ◽  
External Disturbance ◽  
Viscous Friction ◽  
Fine Tuning ◽  
Tracking Performance ◽  
Position Tracking ◽  
Trial And Error ◽  
Hydraulic Actuator ◽  
Tuning Method ◽  
Non Linear System

Abstract Electro-Hydraulic Actuator (EHA) system is a third order non-linear system which is highly suffer from system uncertainties such as Coulomb friction, viscous friction and pump leakage coefficient which makes this system more complicated for the designing of the controller. The Proportional-Integral-Derivative (PID) controller has proposed in this paper to control EHA system and main problem in its application is to tune the parameter to its optimum value. Two different methods are used to tune the PID controller which are trial and error and Ziegler-Nichols method. MATLAB Simulink is used to simulate the system. In order to determine the performance of EHA system for the position tracking. 3 different of external disturbance such as 0N, 5000N and 10000N has been injected into the system. Simulation results show that the Ziegler-Nichols fine tuning method provides the better tracking performance when compared to the trial and error method for every specific disturbance setting. The Ziegler Nichols method provides better disturbance rejection as the performances indexes such as percentage overshoot, settling time and steady state error are not affected by the varying of disturbance.

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