Estimation of Friction and States for Robust Control of Position Servo

2020 ◽  
Vol 142 (9) ◽  
Author(s):  
Shailaja Kurode ◽  
Bhagyashri Tamhane
Keyword(s):  
Robust Control ◽  
System Performance ◽  
Accurate Information ◽  
Position Tracking ◽  
Performance Tracking ◽  
Friction Component ◽  
Accurate Position ◽  
System States ◽  
State Estimations ◽  
And Control

Abstract Friction is an inherent nonlinearity in electromechanical systems. It adversely affects the system performance. The key challenge is to get its accurate information as it is not measurable. This paper proposes a two-observer concept for friction and state estimation. Novelty of proposal includes finite time convergent estimations of the friction component and the system states. These estimations are used to design a robust control for accurate position tracking in servosystem. It is shown that accurate friction and state estimations are obtained, and control efforts are reduced while achieving precise performance. Tracking performance is improved using proposed control. The outcome of the proposed methodology is validated through computer simulations and experimentations.

scholarly journals Decoupled Multi-Loop Robust Control for a Walk-Assistance Robot Employing a Two-Wheeled Inverted Pendulum

Machines ◽  
2021 ◽  
Vol 9 (10) ◽  
pp. 205
Author(s):  
Fu-Cheng Wang ◽  
Yu-Hong Chen ◽  
Zih-Jia Wang ◽  
Chi-Hao Liu ◽  
Pei-Chun Lin ◽  
...  
Keyword(s):  
Robust Control ◽  
Transfer Function ◽  
Inverted Pendulum ◽  
Control Structure ◽  
Position Tracking ◽  
Loop Control ◽  
Wheeled Inverted Pendulum ◽  
Decoupled Control ◽  
Rotational Motions ◽  
Electrical Motors

This paper develops a decoupled multi-loop control for a two-wheeled inverted pendulum (TWIP) robot that can assist user’s with walking. The TWIP robot is equipped with two wheels driven by electrical motors. We derive the system’s transfer function and design a robust loop-shaping controller to balance the system. The simulation and experimental results show that the TWIP system can be balanced but might experience velocity drifts because its balancing point is affected by model variations and disturbances. Therefore, we propose a multi-loop control layout consisting of a velocity loop and a position loop for the TWIP robot. The velocity loop can adjust the balancing point in real-time and regulate the forward velocity, while the position loop can achieve position tracking. For walking assistance, we design a decoupled control structure that transfers the linear and rotational motions of the robot to the commands of two parallel motors. We implement the designed controllers for simulation and experiments and show that the TWIP system employing the proposed decoupled multi-loop control can provide satisfactory responses when assisting with walking.

scholarly journals ДОСЯГНЕННЯ ЕФЕКТИВНОГО РОЗПОДІЛЕНОГО ПЛАНУВАННЯ ЗА ДОПОМОГОЮ ЧЕРГ ПОВІДОМЛЕНЬ У ХМАРІ ДЛЯ БАГАТОЗАДАЧНИХ ОБЧИСЛЕНЬ ТА ВИСОКОПРОДУКТИВНИХ ОБЧИСЛЕНЬ

2020 ◽  
Author(s):  
Старовойтенко Олексій Володимирович
Keyword(s):  
Distributed Systems ◽  
System Performance ◽  
State Of The Art ◽  
Computation Time ◽  
Cloud Services ◽  
Distributed Scheduling ◽  
Message Processing ◽  
Computational Problem ◽  
Control Units ◽  
And Control

Due to the growth of data and the number of computational tasks, it is necessary to ensure the required level of system performance. Performance can be achieved by scaling the system horizontally / vertically, but even increasing the amount of computing resources does not solve all the problems. For example, a complex computational problem should be decomposed into smaller subtasks, the computation time of which is much shorter. However, the number of such tasks may be constantly increasing, due to which the processing on the services is delayed or even certain messages will not be processed. In many cases, message processing should be coordinated, for example, message A should be processed only after messages B and C. Given the problems of processing a large number of subtasks, we aim in this work - to design a mechanism for effective distributed scheduling through message queues. As services we will choose cloud services Amazon Webservices such as Amazon EC2, SQS and DynamoDB. Our FlexQueue solution can compete with state-of-the-art systems such as Sparrow and MATRIX. Distributed systems are quite complex and require complex algorithms and control units, so the solution of this problem requires detailed research.

A New Method for Sensor Degradation Detection, Isolation and Compensation in Linear Systems

2007 ◽  
Author(s):  
Li Jiang ◽  
Dragan Djurdjanovic ◽  
Jun Ni
Keyword(s):  
Degradation Process ◽  
Accurate Information ◽  
Electronic Throttle ◽  
Performance Diagnosis ◽  
Automotive Electronic ◽  
Engineering Designs ◽  
State Space System ◽  
Measurement Devices ◽  
Sensor Degradation ◽  
And Control

The performance of machines and equipment degrades as a result of aging and wear. This decreases performance reliability and increases the potential for faults and failures. To ensure proper functionality of complex systems, advanced technologies for performance diagnosis and control are being incorporated into engineering designs, which requires an ever-increasing number of sensors and measurement devices. Nevertheless, a sensor, just as any other dynamic system, degrades and fails. A faulty sensor may cause process performance degradation, process shut down, or even a fatal accident because it is no longer able to deliver accurate information about the monitored system. Therefore, it is essential to assess sensor performance to ensure system reliability. In this paper, a method is proposed to detect, isolate, and compensate sensor degradation. The numerical algorithm for subspace state space system identification is used to track the changes of the time constants and gains of the sensor and the monitored system. Without imposing requirements for redundant sensors and measurement devices, this method utilizes the fact that sensor readings depict dynamic characteristics of the sensors as well as those of the monitored system. The newly proposed method is verified in angular sensor degradation detection using high-fidelity simulations of an automotive electronic throttle system.

A Rapid Recursive Experimental Approach to Structure/Control Re-Design

1995 ◽  
Author(s):  
Anton Pil ◽  
Haruhiko Asada
Keyword(s):  
System Performance ◽  
Recursive Algorithm ◽  
Descent Method ◽  
Gradient Descent Method ◽  
Control Parameters ◽  
Multiple Control ◽  
Mechatronic Systems ◽  
Loop Control ◽  
Structural Reinforcement ◽  
And Control

Abstract This paper introduces an experimental recursive method for simultaneously changing both the mechanical structure and control design of mechatronic systems in order to improve the system’s overall performance. The method improves a system’s closed-loop control specifications through recursive concurrent structure reinforcement and control gain optimization. By using a process of structural reinforcement, a single prototype structure can be used repeatedly until the system performance goals are achieved. To determine the optimal incremental structure changes, a recursive algorithm based on a gradient descent method and a parameter estimation theory is employed. After the incremental structure reinforcements are applied, the control parameters are optimized with respect to multiple control specifications. Next, the resulting system incorporating the structure and control changes is tested and compared with the desired level of performance. The entire process consisting of experimental evaluation, data analysis, and structure reinforcement is repeated until the system performance achieves the desired level. Simulation experiments are successful in changing both the structural and control parameters of a simplified positioning system and show improvement in the system’s overall settling time.

Electronic surveillance system for COVID-19 virus management in Palestine- an observational study

2021 ◽  
Vol 12 (4) ◽  
pp. 0-0
Keyword(s):  
System Performance ◽  
Surveillance System ◽  
Prevention And Control ◽  
Willingness To Participate ◽  
Electronic Surveillance ◽  
Effective Prevention ◽  
Health Facility Level ◽  
Facility Level ◽  
And Control ◽  
Virus Management

This research investigated the performance of the electronic surveillance system of COVID 19 and assessed its key attributes. The research results for the overall system performance were good (82.81%). The highest attribute score was 100% for representativeness and data completeness and the lowest score was 75.30% for acceptability. The COVID-19 surveillance system is generally simple and accepted by users, although the instability of electricity and the Internet, the benefit from the training on the system, and the lack of willingness to participate in the system at the health facility level had the greatest impact on simplicity and acceptability scores. The quality and completeness of the data enabled stakeholders to carry out the most effective prevention and control activities. System developers indicated that the system has achieved the desired benefit, due to the flexibility and stability of the system and comprehensiveness of geographical coverage.

In Search of the Jerk Element

2021 ◽  
Author(s):  
Zachary P. Belyaev ◽  
Samuel N. Downes ◽  
Philip A. Voglewede
Keyword(s):  
Magnetic Field ◽  
Motion Planning ◽  
System Performance ◽  
Theoretical Background ◽  
Physical Parameters ◽  
Common Elements ◽  
Planning And Control ◽  
Magneto Rheological ◽  
And Control ◽  
The Magnetic Field

Abstract Mechanical components, such as springs, dampers and mass, alter and influence an engineered system’s motion based upon a system’s position, velocity and acceleration, respectively. This paper aims to discover and develop another element (dubbed the damper) which provides a force proportional to a system’s jerk (i.e., the derivative of acceleration) to better engineer a system’s response. By utilizing the known applications of jerk in motion planning and control theory, existing possible physical implementations and uses of jerk and the jerk element are discussed in relation to its influence on the system’s response, specifically vibration. Using a Buckingham Pi approach, the theoretical background of the jerk element is presented and possible physical parameters are combined to show how the jerk element could be created from common elements and parameters. The most promising approach of varying the magnetic field of existing magneto-rheological dampers is developed to give an example of the jerk element along with the difficulties and concerns in developing the jerk element. This paper serves less of a purpose towards answering all questions of the jerk element, but rather focuses more on posing the appropriate questions which sets the stage for an easily realizable future jerk element which can improve system performance.

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