Pneumatic position servo control of magnetic resonance compatible needle insertion robot

2012 ◽  
Vol 227 (7) ◽  
pp. 1469-1480 ◽  
Author(s):  
Shan Jiang ◽  
Wenhao Feng ◽  
Peng Zheng ◽  
Jun Liu ◽  
Jun Yang
Keyword(s):  
Boundary Layer ◽  
Steady State ◽  
Magnetic Resonance ◽  
Sliding Mode Control ◽  
Sliding Mode ◽  
Needle Insertion ◽  
Servo Control ◽  
Mode Control ◽  
Position Servo Control ◽  
Position Servo

This paper presents a control methodology that enables nonlinear model-base control of pulse width modulated (PWM) pneumatic position servo control system of a magnetic resonance (MR) compatible needle insertion robot used for MRI-guided prostate brachytherapy. Sliding mode control with a boundary layer is investigated based on the equivalent continuous-time dynamic model. Considering chattering in sliding mode control applications, especially in motion control of the robot, a fuzzy method is developed to tune the boundary layer of the sliding mode controller. Simulation and experimental results indicate that the controller is effective in both position control and trajectory tracking. With the boundary layer increasing, the steady state error of the response is becoming larger; however the maximum error is less than 0.2 mm. This steady state performance meets the accuracy requirement.

Study of Neuron Sliding Mode Position Control Based on CMAC

2010 ◽  
Vol 439-440 ◽  
pp. 440-444
Author(s):  
Xiao Juan Shi
Keyword(s):  
Sliding Mode Control ◽  
Control Algorithm ◽  
Position Control ◽  
Sliding Mode ◽  
Dynamic Performance ◽  
Servo System ◽  
Mode Control ◽  
Position Servo Control ◽  
Nc Machine ◽  
Position Servo

Combining cerebella model articulation controller with sliding mode control, a novel control algorithm is designed. It adopts neuron PID controller as the teacher signal of CMAC. The control error rapidly tends to zero by adjusting weight of each corresponding unit in CMAC storage. The control algorithm eliminates the chattering in the conventional sliding mode control. It also has high real-time, strong robustness and better convergence. The control algorithm is applied on position servo system of NC machining tool. The experimental results show that it improves dynamic performance and static performance of position servo system. It can realize rapid and exact position servo control of NC machine tool.

scholarly journals Study and Application of Intelligent Sliding Mode Control for Voltage Source Inverters

Energies ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 2544 ◽  
Author(s):  
En-Chih Chang
Keyword(s):  
Steady State ◽  
Sliding Mode Control ◽  
Digital Signal Processor ◽  
Sliding Mode ◽  
Transient Behavior ◽  
Voltage Source ◽  
Accurate Estimation ◽  
Inference System ◽  
Mode Control ◽  
State Error

In this paper, an intelligent sliding mode controlled voltage source inverter (VSI) is developed to achieve not only quick transient behavior, but satisfactory steady-state response. The presented approach combines the respective merits of a nonsingular fast terminal attractor (NFTA) as well as an adaptive neuro-fuzzy inference system (ANFIS). The NFTA allows no singularity and error states to be converged to the equilibrium within a finite time, while conventional sliding mode control (SMC) leads to long-term (infinite) convergent behavior. However, there is the likelihood of chattering or steady-state error occurring in NFTA due to the overestimation or underestimation of system uncertainty bound. The ANFIS with accurate estimation and the ease of implementation is employed in NFTA for suppressing the chatter or steady-state error so as to improve the system’s robustness against uncertain disturbances. Simulation results display that this described approach yields low distorted output wave shapes and quick transience in the presence of capacitor input rectifier loading as well as abrupt connection of linear loads. Experimental results conducted on a 1 kW VSI prototype with control algorithm implementation in Texas Instruments DSP (digital signal processor) support the theoretic analysis and reaffirm the robust performance of the developed VSI. Because the proposed VSI yields remarkable benefits over conventional terminal attractor VSIs on the basis of computational quickness and unsophisticated realization, the presented approach is a noteworthy referral to the designers of correlated VSI applications in future, such as DC (direct current) microgrids and AC (alternating current) microgrids, or even hybrid AC/DC microgrids.

ADAPTIVE SUPER-TWISTING-LIKE SLIDING MODE CONTROL WITH PRESCRIBED PERFORMANCE FOR ROBOT MANIPULATORS

2019 ◽  
Vol 19 (08) ◽  
pp. 1940053
Author(s):  
SHUPENG ZHENG ◽  
XINJIAN NIU ◽  
CHENHUI PENG
Keyword(s):  
Steady State ◽  
Sliding Mode Control ◽  
Sliding Mode ◽  
Robot Manipulator ◽  
Robot Manipulators ◽  
Parameter Tuning ◽  
Unknown Boundary ◽  
Surgical Robots ◽  
Prescribed Performance ◽  
Mode Control

In order to minimize the involuntary tremor of surgeon’s hands, the surgical robots are widely applied in the minimally invasive surgeries. However, unlike ordinary robots, the surgical robots require that the manipulator has high precision and strong anti-disturbance ability. Besides that, the manipulators of surgical robots must be able to move smoothly and respond quickly to the surgeon’s instructions during conducting tasks. To solve aforementioned problems, this paper describes a super-twisting sliding mode controller for the robot manipulator. The basic law is combined with the adaptive term to overcome the unknown disturbances and structural uncertainties, and with the prescribed performance allowing to influence the error dynamics. To ensure the robot system has good transient and steady-state performances, the transformation function of tracking errors is devised. Through using transformed errors, we attain the surface of sliding mode and propose a modified structure of traditional super-twisting algorithm. Considering the derivative of lumped disturbance has unknown boundary, a novel adaptive law is derived for the modified super-twisting sliding mode control which does not require the boundary of disturbance. Simulation experiments showed that the proposed control algorithm not only improves the tracking performance of surgical robot manipulators, but also facilitates the parameter tuning of controller. The devised robot manipulators are also potentially applicable to telesurgery where the steady-state response of surgical robots is required.

scholarly journals Discrete Sliding Mode Control Strategy for Start-Up and Steady-State of Boost Converter

Energies ◽  
2019 ◽  
Vol 12 (15) ◽  
pp. 2990
Author(s):  
Yang ◽  
Liao
Keyword(s):  
Steady State ◽  
Sliding Mode Control ◽  
Control Strategy ◽  
Sliding Mode ◽  
Boost Converter ◽  
Lyapunov Theory ◽  
Signal Model ◽  
Switching Surface ◽  
Mode Control ◽  
Start Up

Since the zero initial conditions of the boost converter are far from the target equilibrium point, the overshoot of the input current and the output voltage will cause energy loss during the start-up process when the converter adopts the commonly used small-signal model design control method. This paper presents a sliding mode control strategy that combines two switching surfaces. One switching surface based on the large-signal model is employed for the start-up to minimize inrush current and voltage overshoot. The stability of this strategy is verified by Lyapunov theory and simulation. Once the converter reaches the steady-state, the other switching surface with PI compensation of voltage error is employed to improve the robustness. The latter switching surface, which is adopted to regulate the voltage, can not only suppress the perturbation of input voltage and load, but also achieve a better dynamic process and a zero steady-state error. Furthermore, the discrete sliding mode controller is implemented by digital signal processor (DSP). Finally, the results of simulation, experiment and theoretical analysis are consistent.

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