Functional Persistence of Excitation and Observability for Learning Control Systems

1992 ◽  
Vol 114 (3) ◽  
pp. 500-507 ◽  
Author(s):  
J. B. Moore ◽  
R. Horowitz ◽  
W. Messner
Keyword(s):  
Integral Operator ◽  
Control Systems ◽  
Learning Process ◽  
Influence Function ◽  
Adaptive Systems ◽  
Control Algorithm ◽  
Repetitive Control ◽  
Natural Generalization ◽  
Function Learning ◽  
Finite Dimensional

Adaptive systems involving function learning can be formulated in terms of integral equations of the first kind, possibly with separable, finite-dimensional kernels. The learning process involves estimating the influence functions (Messner et al., 1989). To achieve convergence of the influence function estimates and exponentially stability, it is important to have persistence of excitation in the training tasks. This paper develops the concept of functional persistence of excitation (PE), and the associated concept of functional uniform complete observability (UCO). Relevant PE and UCO properties for linear systems are developed. For example, a key result is that uniform complete observability in this context is maintained under bounded integral operator output injection—a natural generalization of the corresponding finite dimensional result. This paper also demonstrates the application of the theory to linear error equations associated with a repetitive control algorithm.

Passive Finite-Dimensional Repetitive Control of Robot Manipulators

2008 ◽  
Vol 16 (3) ◽  
pp. 570-576 ◽  
Author(s):  
J. Kasac ◽  
B. Novakovic ◽  
D. Majetic ◽  
D. Brezak
Keyword(s):  
Robot Manipulators ◽  
Repetitive Control ◽  
Finite Dimensional

Frequency Shaped Semi-Active Control for Magnetorheological Fluid-Based Vibration Control Systems

2013 ◽  
Author(s):  
Young-Tai Choi ◽  
Norman M. Wereley ◽  
Gregory J. Hiemenz
Keyword(s):  
Vibration Control ◽  
Control Systems ◽  
Active Control ◽  
Control Algorithm ◽  
Active Vibration Control ◽  
Control Algorithms ◽  
Model Parameters ◽  
Mr Fluid ◽  
Control Current ◽  
Active Vibration

Novel semi-active vibration controllers are developed in this study for magnetorheological (MR) fluid-based vibration control systems, including: (1) a band-pass frequency shaped semi-active control algorithm, (2) a narrow-band frequency shaped semi-active control algorithm. These semi-active vibration control algorithms designed without resorting to the implementation of an active vibration control algorithms upon which is superposed the energy dissipation constraint. These new Frequency Shaped Semi-active Control (FSSC) algorithms require neither an accurate damper (or actuator) model, nor system identification of damper model parameters for determining control current input. In the design procedure for the FSSC algorithms, the semi-active MR damper is not treated as an active force producing actuator, but rather is treated in the design process as a semi-active dissipative device. The control signal from the FSSC algorithms is a control current, and not a control force as is typically done for active controllers. In this study, two FSSC algorithms are formulated and performance of each is assessed via simulation. Performance of the FSSC vibration controllers is evaluated using a single-degree-of-freedom (DOF) MR fluid-based engine mount system. To better understand the control characteristics and advantages of the two FSSC algorithms, the vibration mitigation performance of a semi-active skyhook control algorithm, which is the classical semi-active controller used in base excitation problems, is compared to the two FSSC algorithms.

Stability Robustness of Repetitive Control Systems With Zero Phase Compensation

1990 ◽  
Vol 112 (3) ◽  
pp. 320-324 ◽  
Author(s):  
C. C. H. Ma
Keyword(s):  
Control System ◽  
Large Class ◽  
Control Systems ◽  
Repetitive Control ◽  
Tracking Performance ◽  
Three Solutions ◽  
Phase Compensation ◽  
Saturation Nonlinearity ◽  
Stability Robustness ◽  
Zero Phase

It is shown that a special zero phase control (ZPC) system introduced by Tomizuka is L∞ stable against a large class of common nonlinearities. However, it still suffers from the generic nonrobustness problem associated with a linear repetitive control system when subjected to a saturation nonlinearity. For the special ZPC system, however, three solutions exist for the problem, two of which do not degrade the repetitive tracking performance.

scholarly journals Braking Control for Improving Ride Comfort

2018 ◽  
Vol 166 ◽  
pp. 02002 ◽  
Author(s):  
Jonghyup Lee ◽  
Seibum Choi
Keyword(s):  
Control Systems ◽  
Control Algorithm ◽  
Ride Comfort ◽  
Low Risk ◽  
Vehicle Safety ◽  
Phase Lag ◽  
Vehicle Performance ◽  
High Speeds ◽  
Braking Control ◽  
The Moment

While many vehicle control systems focus on vehicle safety and vehicle performance at high speeds, most driving conditions are very low risk situations. In such a driving situation, the ride comfort of the vehicle is the most important performance index of the vehicle. Electro mechanical brake (EMB) and other brake-by-wire (BBW) systems have been actively researched. As a result, braking actuators in vehicles are more freely controllable, and research on improving ride comfort is also possible. In this study, we develop a control algorithm that dramatically improves ride comfort in low risk braking situations. A method for minimizing the inconvenience of a passenger due to a suddenly changing acceleration at the moment when the vehicle is stopped is presented. For this purpose, an acceleration trajectory is generated that minimizes the discomfort index defined by the change in acceleration, jerk. A controller is also designed to track this trajectory. The algorithm that updates the trajectory is designed considering the error due to the phase lag occurring in the controller and the plant. In order to verify the performance of this controller, simulation verification is completed using a car simulator, Carsim. As a result, it is confirmed that the ride comfort is dramatically improved.

Analysis and comparison of the two sectoring approaches in elevator traffic systems

2019 ◽  
Vol 40 (5) ◽  
pp. 611-626
Author(s):  
Lutfi Al-Sharif ◽  
Ahmad Hammoudeh ◽  
Jannat Al-Saidi
Keyword(s):  
Control Systems ◽  
Traffic Control ◽  
Control Algorithm ◽  
Dynamic Allocation ◽  
Practical Application ◽  
Round Trip ◽  
Allocation Method ◽  
Group Control ◽  
Static Allocation ◽  
Traffic Systems

Sectoring is a group control algorithm that is used in elevator traffic control systems by grouping passengers that have common destinations or common origins into elevator cars that serve these floors. The building is split into sectors usually comprising contiguous floors. Two different alternative algorithms for sectoring are discussed in this paper. The first approach is based on dynamic allocation with equal sector allocation. The second approach is based on static allocation with unequal sector sizes. Under static allocation, the same elevator car is allocated to the same sector in every round trip. Under dynamic allocation, each elevator car is allocated to a different sector in each round trip. Under the dynamic allocation scheme suggested in this paper, the elevator cars are sequenced to the various sectors in the buildings in a round-robin fashion. It is important to note that under both schemes, the provided (relative) handling capacity of different sectors is equalised. Five different buildings have been analysed using the two suggested sectoring algorithms. The building is first designed by finding the required number and speed of elevators assuming conventional control. Each building is then analysed using one of the two suggested sectoring algorithms. In order to compare the performance of the two sectoring algorithms, the provided (relative) handling capacity is calculated. The provided (relative) handling capacity of the two suggested algorithms is then compared. Very little difference was found between the two algorithms. The dynamic sectoring with equal sector sizes offers the convenience of having equal sector sizes. The static sectoring with unequal sector sizes is more convenient for passengers that are familiar with the building. Practical application: This paper analyses two different options for sectoring the control system of an elevator system in a building. Each of the two sectoring methods is suitable for different situations. The dynamic allocation method is more suitable for destination group control systems and offers the group controller more flexibility. The static allocation method with unequal sector sizes ensures that the passengers remain familiar with the elevators that they use to get to their floors. The programmer of the elevator group controller can programme both methods in the controller and allow it to switch to the most suitable algorithm depending on the prevailing conditions.

scholarly journals Controllability of Semilinear Systems with Multiple Variable Delays in Control

Mathematics ◽  
2020 ◽  
Vol 8 (11) ◽  
pp. 1955
Author(s):  
Jerzy Klamka
Keyword(s):  
Control Systems ◽  
Time Variable ◽  
Multiple Time ◽  
Variable Delays ◽  
Finite Dimensional ◽  
Multiple Variable ◽  
Variable Point ◽  
Admissible Controls ◽  
Point Delays ◽  
Controllability Conditions

In the paper semilinear, finite-dimensional, control systems with multiple time variable point delays in admissible controls are considered. Using Rothe’s fixed-point theorem, sufficient controllability conditions are formulated. The results of the paper are generalization to many time variable delays in control, of the results published recently.

scholarly journals PID Controller Implemented in Festo CDPX

2019 ◽  
Vol 260 ◽  
pp. 02008
Author(s):  
Primož Podržaj
Keyword(s):  
Control Systems ◽  
Pid Controller ◽  
Control Algorithm ◽  
Closed Loop ◽  
Pi Control ◽  
Programmable Logic ◽  
Educational Tool ◽  
Level Control ◽  
Loop Control ◽  
Machine Interface

In this paper, we describe the procedure for the implementation of the PID controller in the Festo CDPX operator unit. These units enable the execution of the control algorithm and human machine interface in a single unit. In our laboratory the unit is used to teach the students about the basics of control systems. For this purpose, one of the most common closed loop control systems for the education purposes was selected. It is a water level control system. In this paper the design of the whole system is presented. The need for a PI control algorithm is also explained. The programming of the operator unit CDPX, both in Festo CoDeSys and Designer Studio is explained. Such a simple system has turned out to be a great educational tool for Control Theory and Programmable Logic Controller related subjects.

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