Realization of First-Order All-Pass Filter Using Four Terminal Floating Nullor

2006 ◽  
Author(s):  
Mustafa Sayginer ◽  
Hakan Kuntman
Keyword(s):  
Pass Filter ◽  
First Order ◽  
Four Terminal Floating Nullor

scholarly journals Stabilization of the Magnetic Levitation System

2021 ◽  
Vol 11 (21) ◽  
pp. 10369
Author(s):  
Štefan Chamraz ◽  
Mikuláš Huba ◽  
Katarína Žáková
Keyword(s):  
Closed Loop ◽  
Magnetic Levitation ◽  
Internal Model Control ◽  
Pass Filter ◽  
Low Pass Filter ◽  
First Order ◽  
Model Based ◽  
Model Control ◽  
Levitation System ◽  
Magnetic Levitation System

This paper contributes toward research on the control of the magnetic levitation plant, representing a typical nonlinear unstable system that can be controlled by various methods. This paper shows two various approaches to the solution of the controller design based on different closed loop requirements. Starting from a known unstable linear plant model—the first method is based on the two-step procedure. In the first step, the transfer function of the controlled system is modified to get a stable non-oscillatory system. In the next step, the required first-order dynamic is defined and a model-based PI controller is proposed. The closed loop time constant of this first-order model-based approach can then be used as a tuning parameter. The second set of methods is based on a simplified ultra-local linear approximation of the plant dynamics by the double-integrator plus dead-time (DIPDT) model. Similar to the first method, one possible solution is to stabilize the system by a PD controller combined with a low-pass filter. To eliminate the offset, the stabilized system is supplemented by a simple static feedforward, or by a controller proposed by means of an internal model control (IMC). Another possible approach is to apply for the DIPDT model directly a stabilizing PID controller. The considered solutions are compared to the magnetic levitation system, controlled via the MATLAB/Simulink environment. It is shown that, all three controllers, with integral action, yield much slower dynamics than the stabilizing PD control, which gives one motivation to look for alternative ways of steady-state error compensation, guaranteeing faster setpoint step responses.

Oscillations in a first-order all-pass filter

1970 ◽  
Vol 29 (1) ◽  
pp. 83-91 ◽  
Author(s):  
P. C. SEN ◽  
D. PATRANABIS
Keyword(s):  
Pass Filter ◽  
First Order

scholarly journals Collision detection algorithm for collaborative robots considering joint friction

2018 ◽  
Vol 15 (4) ◽  
pp. 172988141878899 ◽  
Author(s):  
Juliang Xiao ◽  
Qiulong Zhang ◽  
Ying Hong ◽  
Guodong Wang ◽  
Fan Zeng
Keyword(s):  
Collision Detection ◽  
Angular Acceleration ◽  
Detection Algorithm ◽  
Friction Model ◽  
Frequency Noise ◽  
Robot Interaction ◽  
Pass Filter ◽  
Low Pass Filter ◽  
First Order ◽  
Different Response

This article proposes a collision detection algorithm without external sensors that can detect potential collisions in man–robot interaction. The algorithm is based on a modified first-order momentum deviation observer that also takes friction into account. The collision detection algorithm uses joint angles, angular velocities, and torques during the detection process, without any need to consider angular acceleration. The algorithm also uses an accurate friction model that is based on a Stribeck model with second-order Fourier series compensation. The friction model is applied in advance so that compensation can be made in real time during collision detection. Identification data are filtered through a first-order low-pass filter to reduce high-frequency noise. In order to verify the algorithm, a simulation and experiment were carried out using a collaborative robot experimental platform. The results confirmed that collisions can be detected by setting appropriate threshold values. Different possible responses can be implemented according to different response strategies, with the ultimate arbiter being that collision forces are kept strictly within ordinary human tolerances. This makes sure that safety can be preserved in man–robot interaction processes.

Sign in / Sign up

Export Citation Format

Share Document