scholarly journals Mechatronic Control System for a Compliant and Precise Pneumatic Rotary Drive Unit

Actuators ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 1 ◽  
Author(s):  
Johannes T. Stoll ◽  
Kevin Schanz ◽  
Andreas Pott

Robots that enable safe human-robot collaboration can be realized by using compliant drive units. In previous works, different mechanical designs of compliant pneumatic rotary drive units with similar characteristics have been presented. In this paper, we present the overall control approach that we use to operate one of these compliant pneumatic rotary drive units. We explain the mechanical design and derive the differential equation that describes the dynamics of the system. In order to successfully operate a pneumatic drive unit with three or more working chambers, the torque specified by the controller has to be split up onto the working chambers. We transfer the well-known field-oriented control approach from electric motors to the investigated pneumatic drive unit to create such a torque mapping. Moreover, we develop optimized torque mappings that are tailored to work with this type of drive unit. Furthermore, we introduce and compare two control algorithms based on different implementations of state feedback to realize position control. Finally, we present the step responses that we achieve when we implement either one of the control algorithms in combination with the different torque mappings.

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Xiaojun Wang ◽  
Jiankun Sun ◽  
Guipu Li

This paper investigates the finite-time position tracking control problem of pneumatic servo systems subject to hard nonlinearities and various disturbances. A finite-time disturbance observer is firstly designed, which guarantees that the disturbances can be accurately estimated in a finite time. Then, by combining disturbances compensation and state feedback controller together, a nonsmooth composite controller is developed based on sliding mode control approach and homogeneous theory. It is proved that the tracking errors under the proposed composite control approach can be stabilized to zero in finite time. Moreover, compared with pure state feedback control, the proposed composite control scheme offers a faster convergence rate and a better disturbance rejection property. Finally, numerical simulations illustrate the effectiveness of the proposed control scheme.


2018 ◽  
Vol 8 (1) ◽  
pp. 142-153
Author(s):  
Vu Trieu Minh ◽  
Mart Tamre ◽  
Even Sekhri

AbstractThis paper proposes the mathematical modeling and robust control algorithms for linear belt system with the help of sliding mode control approach. Due to the elasticity of the belt, the presence of frictions, and the un-modeled dynamics, conventional controllers cannot provide precise position control of carriage. Dealing with this kind of system, a robust controller is needed and the chattering-free sliding mode control (SMC) approach is used to design the robust controller. A belt stretching estimator is also incorporated into the control law. Simulations show that the system is free from chattering and robust to disturbances. The reference tracking position is performed with the minimal errors to an extent that can be considered negligible. The time for reaching the reference tracking position is very fast. The system is safe for all mechanical and electrical devices.


Author(s):  
S. Hajji ◽  
A. Ayadi ◽  
M. Smaoui ◽  
T. Maatoug ◽  
M. Farza ◽  
...  

This paper investigates the applicability of two state feedback controllers for a class of uniformly controllable and observable nonlinear systems. The first one is based on an appropriate high gain control principle that has been developed by duality from the high gain observer principle. The state feedback control gain is particularly provided by a synthesis function satisfying a well-defined condition, leading thereby to a unification of the high gain control designs. The second one is a backstepping controller that has been developed from a suitable combination of the backstepping control approach bearing in mind the high gain control principle pursued for the first controller design. A common engineering design feature that is worth to be mentioned consists in properly formulating their underlying control problems as a regulation problem involving a suitable reference model with respect to the structure of the system as well as the control design principle under consideration. Of fundamental interest, the involved reference model is systematically derived thanks to the flatness and backstepping principles using an appropriate Lyapunov approach. An experimental evaluation is carried out to illustrate the efficiency of the proposed nonlinear controllers.


2015 ◽  
Vol 135 (11) ◽  
pp. 1376-1385
Author(s):  
Kentaro Ohnuma ◽  
Hirohito Sumikura ◽  
Tomonori Tsukiya ◽  
Eisuke Tatsumi ◽  
Yoshiyuki Taenaka ◽  
...  

Complexity ◽  
2019 ◽  
Vol 2019 ◽  
pp. 1-14 ◽  
Author(s):  
Firas Turki ◽  
Hassène Gritli ◽  
Safya Belghith

This paper proposes a state-feedback controller using the linear matrix inequality (LMI) approach for the robust position control of a 1-DoF, periodically forced, impact mechanical oscillator subject to asymmetric two-sided rigid end-stops. The periodic forcing input is considered as a persistent external disturbance. The motion of the impacting oscillator is modeled by an impulsive hybrid dynamics. Thus, the control problem of the impact oscillator is recast as a problem of the robust control of such disturbed impulsive hybrid system. To synthesize stability conditions, we introduce the S-procedure and the Finsler lemmas by only considering the region within which the state evolves. We show that the stability conditions are first expressed in terms of bilinear matrix inequalities (BMIs). Using some technical lemmas, we convert these BMIs into LMIs. Finally, some numerical results and simulations are given. We show the effectiveness of the designed state-feedback controller in the robust stabilization of the position of the impact mechanical oscillator under the disturbance.


Actuators ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 51
Author(s):  
Jozef Živčák ◽  
Michal Kelemen ◽  
Ivan Virgala ◽  
Peter Marcinko ◽  
Peter Tuleja ◽  
...  

COVID-19 was first identified in December 2019 in Wuhan, China. It mainly affects the respiratory system and can lead to the death of the patient. The motivation for this study was the current pandemic situation and general deficiency of emergency mechanical ventilators. The paper presents the development of a mechanical ventilator and its control algorithm. The main feature of the developed mechanical ventilator is AmbuBag compressed by a pneumatic actuator. The control algorithm is based on an adaptive neuro-fuzzy inference system (ANFIS), which integrates both neural networks and fuzzy logic principles. Mechanical design and hardware design are presented in the paper. Subsequently, there is a description of the process of data collecting and training of the fuzzy controller. The paper also presents a simulation model for verification of the designed control approach. The experimental results provide the verification of the designed control system. The novelty of the paper is, on the one hand, an implementation of the ANFIS controller for AmbuBag pressure control, with a description of training process. On other hand, the paper presents a novel design of a mechanical ventilator, with a detailed description of the hardware and control system. The last contribution of the paper lies in the mathematical and experimental description of AmbuBag for ventilation purposes.


2021 ◽  
Vol 1783 ◽  
pp. 012057
Author(s):  
Iswanto ◽  
Nia Maharani Raharja ◽  
Alfian Ma’arif ◽  
Yogi Ramadhan ◽  
Phisca Aditya Rosyady

2021 ◽  
Vol 13 (2) ◽  
Author(s):  
Emmanouil Spyrakos-Papastavridis ◽  
Jian S. Dai

Abstract This paper attempts to address the quandary of flexible-joint humanoid balancing performance augmentation, via the introduction of the Full-State Feedback Variable Impedance Control (FSFVIC), and Model-Free Compliant Floating-base VIC (MCFVIC) schemes. In comparison to rigid-joint humanoid robots, efficient balancing control of compliant bipeds, powered by Series Elastic Actuators (or harmonic drives), requires the design of more sophisticated controllers encapsulating both the motor and underactuated link dynamics. It has been demonstrated that Variable Impedance Control (VIC) can improve robotic interaction performance, albeit by introducing energy-injecting elements that may jeopardize closed-loop stability. To this end, the novel FSFVIC and MCFVIC schemes are proposed, which amalgamate both collocated and non-collocated feedback gains, with power-shaping signals that are capable of preserving the system's stability/passivity during VIC. The FSFVIC and MCFVIC stably modulate the system's collocated state gains to augment balancing performance, in addition to the non-collocated state gains that dictate the position control accuracy. Utilization of arbitrarily low-impedance gains is permitted by both the FSFVIC and MCFVIC schemes propounded herein. An array of experiments involving the COmpliant huMANoid reveals that significant balancing performance amelioration is achievable through online modulation of the full-state feedback gains (VIC), as compared to utilization of invariant impedance control.


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